A2 connection

[scott32]

i had my controller increased from a 300 amp to a 400 amp. i also added the 4ga wires. my kart is a 1999 48V series kart. the wiring for the A2 connection went to the controller first then a wire to the motor. question is do i need the connection to the controller or should i just run it staright to the motor and bypass this connection to the controller. also i have the 3.75 hp motor. i am asking because i read somewhere that you do not have to run this connection on the controller. and i also have the white rogers heavy duty solenoid.

thanks scott

[Carts Zone]

A2 deals with switching the cart from foward to reverse or vise versa while moving.

The A2 bus bar on the controllers
prevents the drive wheels from locking up. As the
motor turns into a generator the voltage at the A2 bus
bar increases. The controller senses this condition and
shorts out the armature through the plugging diode.
Shorting the armature prevents the feedback loop from
creating a strong field. The controller can then
modulate the field current to control braking force.

Reversing direction without plug brake
When the direction o the motor is changed, the field
polarity reverses. This is what causes the motor to spin
the opposite direction. When under power, the field
reverses, but the momentum of the vehicle is keeps the
armature from reversing. The motor then turns into a
generator. As the voltage generated by the motor flows
back to through the controller and field winding, the
current increases. As the current increases the field
intensity increases causing more voltage to be
generated. This feedback loop builds quickly to the
point where the field intensity is so strong it will stop
the armature from spinning. If the vehicle is still
moving, this will cause the drive wheels to lock up. This
energy buildup happens very quickly inside the motor
and controller.

How it works
The controller detects plugging by comparing the
voltage across a diode connected to the A2 bus bar. If
there is voltage across the diode, the controller
switches the PWM of the controller to a low duty and
frequency mode. A “whine” may be heard during plug
braking, this is normal a normal condition of the
reduced frequency of the PWM. Using the slower and
lower powered, allows the controller to safely control
the speed of the armature.
As the motor slows, the armature voltage drops. This
results in a loss of braking torque as speed approaches
zero and no braking at a stop. When the voltage across
the diode drops to zero, the controller resumes normal
PMW operation. The armature now spins in the reverse
direction. The energy dissipated by plug braking is
converted into heat in the motor and controller.

Plug braking is an essential feature for some
applications. When the direction reverses on a series
wound motor, plug braking turns a dangerous situation
into a safe one. The controlled braking and smooth
stop protects not only the operator but the motor and
the controller.

[scott32]

ok. sounds like i need to leave it alone. does it matter if i run the 4ga wire to the motor instead of the controller and just leave the 6 ga wire from the controller to the motor.

thanks scott

[roady89]

Originally Posted by scott32

ok. sounds like i need to leave it alone. does it matter if i run the 4ga wire to the motor instead of the controller and just leave the 6 ga wire from the controller to the motor.

thanks scott

If your not gonna do it ALL theres no since in doing any of it.

[AugustaResident]

Agreed........I performed a 36 to 48 upgrade on an E-Z-GO and with the 650 amp controller and HP motor, I was one wire short of a total upgrade. Ran the cart anyways and that one 6 ga wire almost acted like a fuse. Do em all or do em none.

[scott32]

i did all of the wires except the 1 from the A2 on motor to the controller and that is why i connected the 1 from the fr switch to the motor first. then ran the original from the motor to controller on the A2. i was assuming this only feeds a amp or volt signal to the controller. does that make sense.

thanks scott